Points to note are that:
when a solute dissolves, mass is conserved.
when a solute dissolves, the solute and solvent particles intermingle.
increasing the temperature increases the rate of dissolving.
Points to note are that:
when a solid is added to a liquid, eventually no more will dissolve;
different masses of different solids dissolve in the same volume of a particular solvent.
that solids can dissolve in liquids other than water.